You go to school first before you get a job based on the acquired skills from the school. You take professional classes and certification exams and leverage them latter on for a better job or increased pay. And it's like that with everything we learn, both informal knowledge or formal knowledge.
You have to prioritize learning. Learn as much as you can at every stage of your life. Everything you learn will pay off someday. Also when a window of learning is missed, you might never come across another. If after secondary school you went straight into the job market and worked for 10 years. Then you found out that you need a B.Sc and MBA to progress in your career, how easy will it be to acquire them when you now have to juggle schooling with a full-time work and a young family? You missed that window of learning when you skipped university for a job.
I have found that a lot of the skills that have opened doors for me were skills I acquired out of curiosity and not because I originally planned to make use of them in my career. Always learning as much as I can about everything that interests me has made it possible for me to access opportunities that depended on those learning.
You will not always have time to acquire a skill or learning at the point you need it. To reduce any regret you'll have and increase the luck that'll come your way, you have to prioritize learning. Learn all you can while there's no pressure to hit a targeted opportunity. Learn always. Every new skill you get make more opportunities come your way.